Mylone (3,5-dimethyl tetrahydro-1,3,5,2H thiadiazine-2-thione) 
One hour after oral administration to rats, unhydrolyzed mylone was 
found in the stomach. Carbon disulfide equivalent to 1-3% of the dose was 
found in the stomach and 1.5% of the dose was found in exhaled air. After 
either intravenous or oral administration of mylone to dogs, CS, was found 
in the exhaled air of dogs (1334). 
Activation or degradation of mylone in soil was dependent on moisture 
or free water and was a function of time and temperature. Formaldehyde was 
the first breakdown product and appeared within 15 minutes at room tempera- 
ture. Methylamino methyldithiocarbamate appeared next and in turn formed 
CH3NH», methyl isothiocyanate, and hydrogen sulfide. Monomethyl amine and 
hydrogen sulfide reacted with formaldehyde to form methyl amino methanol, 
dimethyl amino methane, and 1,3,5-trithiocyclohexane. Eventually this pro- 
ceeded to C09, NH3, SOo, and H»0. The methyl isothiocyanate reacted with 
H,0 to yield CO 9, HoS, and CH3NH, (1418). Methyl isothiocyanate may also 
react with ammonia, amines or sulfhydryls if present (960, 1052, 1054, 1418). 
Studies indicated that clays--attapulgite, kaolinite, bentonite--act 
catalytically in the initial breakdown of mylone and facilitate the release 
of methylisothiocyanate (1055). 
Mylone was not hydrolyzed within 7 days to an appreciable degree in 
water at 30°C. Increased temperature or the presence of acid increased 
hydrolysis and yielded 1 of carbon disulfide, two of formaldehyde, and two 
of methylamine per molecule of mylone (1334). 
Methyl isothiocyanate release was found to be a first order reaction 
and varied directly with temperature and moisture; increased with soil pH 
over the range of 2.3 to 6.5 but fell off at values up to pH 7.7; decreased 
with increased clay or peat content; but was not dependent upon soil organisms 
(10525, 
255 
